Octet means presence of a total of 8 electrons in its valence shell while in case of duplet only 2 electrons are present in valence shell.
Matter is everything and everything is made of matter, everything physical at least
13
Al
Aluminum
Atomic mass 26.982
1. A. All the elements in the column have similar chemical properties.
2. Substances on the periodic table cannot be broken down into other substances and are therefore elements.
